The present invention is directed to a wrench, and more particularly to a wrench having a locking mechanism for holding open the jaws of the wrench for easy removal of a workpiece from the jaws.
Previously, adjustable wrenches have been provided with a moveable jaw that permits use of the wrench with work pieces, e.g., pipes and nuts, of varying sizes. However, once the jaws of the wrench are closed on the work piece, the work piece can be removed only by manually opening the moveable jaw away from the work piece. Attempts have been made to provide wrenches where the user can open the moveable jaw without actually grasping and pulling the moveable jaw. However, in many such designs, a significant amount of force must nonetheless be exerted by the user to open the jaw.
The present invention is directed to an improved wrench having a moveable jaw whereby minimal force is necessary to open the moveable jaw to remove the work piece. In one embodiment, the invention is directed to a wrench for applying a force to a work piece comprising a handle having proximal and distal ends and top and bottom surfaces. A fixed jaw is mounted at the distal end of the handle, and a moveable jaw is pivotally mounted at the distal end of the handle. A biasing means is mounted in the handle for biasing the moveable jaw toward the fixed jaw. A slidable button is mounted on the top surface of the handle. A connector is provided having a distal end fixedly attached to the moveable jaw and a proximal end fixedly attached to the slidable button. The wrench further comprises means for locking the slidable button in a fixed position to hold the moveable jaw in an open position.
In a preferred embodiment, the invention is directed to a wrench having a handle and fixed and moveable jaws, as described above. The handle has a slot extending therethrough with at least one groove extending downward from the slot. A spring is mounted in the handle having a distal end in contact with the moveable jaw for biasing the moveable jaw toward the fixed jaw. A slidable button is mounted on the top surface of the handle, with a spring mounted between the slidable button and the top surface of the handle. The wrench further comprises a connector having a distal end fixedly attached to the movable jaw and a proximal end fixedly attached to the slidable button by a pin. In operation, the pin rides in the slot and fits in the groove.
By the above designs, when the user desires to remove the wrench from the work piece, he pushes the wrench distally toward the work piece. The work piece exerts a force on the proximal end of the moveable jaw, counteracting the biasing force of the spring and thereby opening the jaw. When the jaw opens, the connector is moved proximally, thus moving the slidable button proximally. This movement causes the pin to move proximally within the slot. When the moveable jaw is opened far enough for the work piece to be removed, the user pushes downward on the slidable button, thereby holding open the moveable jaw. Further, in the preferred embodiment, pushing on the slidable button forces the pin into the groove, further locking the moveable jaw in an open position so that, even if the user releases the slidable button, the moveable jaw will remain open.